US Gallons to US Fluid Ounces
1 us gallon = 128 us fluid ounces (fl oz)
Convert us gallons to us fluid ounces instantly. 1 us gallon = 128 us fluid ounces. Free, accurate, with conversion table and formula.
US Gallon (gal)
US Fluid Ounce (fl oz)
| Unit | 1 gal equals |
|---|---|
| Milliliter (ml) | 3,785.41 |
| Liter (L) | 3.78541 |
| Cubic Meter (m³) | 0.00378541 |
| Cubic Centimeter (cm³) | 3,785.41 |
| US Teaspoon (tsp) | 768 |
| US Tablespoon (tbsp) | 255.999 |
| US Fluid Ounce (fl oz) | 128 |
| US Cup (cup) | 15.7725 |
| US Pint (pt) | 8 |
| US Quart (qt) | 4 |
| US Gallon (gal) | 1 |
| Imperial Gallon (imp gal) | 0.832674 |
How to convert us gallons to us fluid ounces
- 1Take your value in us gallons (gal).
- 2Multiply by 128.
- 3The result is your value in us fluid ounces (fl oz).
US Gallons to US Fluid Ounces conversion table
| US Gallons (gal) | US Fluid Ounces (fl oz) |
|---|---|
| 1 | 128 |
| 2 | 256 |
| 5 | 640 |
| 10 | 1,280 |
| 25 | 3,200 |
| 50 | 6,400 |
| 100 | 12,800 |
| 250 | 32,000 |
| 500 | 64,000 |
| 1,000 | 128,000 |
Frequently asked
How many us fluid ounces are in a us gallon?
1 us gallon equals 128 us fluid ounces (fl oz).
How do I convert us gallons to us fluid ounces?
Multiply the number of us gallons by 128 to get us fluid ounces.
What is 10 us gallons in us fluid ounces?
10 gal equals 1,280 fl oz.
What is 100 us gallons in us fluid ounces?
100 gal equals 1.280e+4 fl oz.
How do I convert us fluid ounces back to us gallons?
Multiply us fluid ounces by 0.0078125 (the reciprocal) or use the swap button above.
Where you'll actually use this
Volume measures three-dimensional capacity — how much liquid a container holds or how much space an object occupies. Metric uses liters and milliliters; imperial uses gallons, quarts, pints, cups, and fluid ounces.
- Cooking
US recipes use cups and tablespoons; metric recipes use ml. A US cup is 236.6 ml — not 250 ml as in metric cups.
- Fuel
Pump prices show gallons in the US, liters almost everywhere else.
- Beverages
A US fluid ounce (29.57 ml) is slightly smaller than a UK fluid ounce (28.41 ml).
Common mistakes to avoid
- US gallon ≠ UK gallon
A US gallon is 3.785 L, a UK (imperial) gallon is 4.546 L — about 20% larger.
- Cups aren't universal
US cup = 236.6 ml. UK cup = 284 ml. Metric cup = 250 ml. Match the recipe origin.
Did you know?
At 4 °C exactly one liter of pure water weighs one kilogram — the original metric definition.
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